Wireless communication networks continue to increase in demand as consumers flock toward mobile computing devices and as manufacturers continue to develop wireless devices with greater capabilities and features. Many consumers use personal wireless networks in their homes. While these networks are easy to install and provide considerable bandwidth, they do not provide communication over a very large distance. Many cities have begun arranging wireless networks on a larger scale to provide wireless communication over a larger area.
Numerous types of wireless networks and network protocols exist. Wireless local area networks (WLAN) typically include one of the various Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard wireless protocols, first promulgated in 1999. These protocols include IEEE 802.11a, 802.11b, 802.11g, and 802.11n, which operate at different spectrum bands and/or different multiplexing or spread spectrum schemes to deliver various bit rates to devices on a wireless network. Any of these IEEE 802.11 networks may be referred to as a “WiFi” network.
Another example of a wireless network technology is the Bluetooth wireless protocol promulgated by the Bluetooth Special Interest Group, Inc. Sometimes referred to as personal area networks or PAN, networks employing the Bluetooth wireless protocol employ short-range communications technology facilitating data transmission over short distances from fixed and/or mobile devices. Bluetooth networks also employ frequency hopping spread spectrum, and may achieve a gross data rate of 1 megabit per second (Mb/s) (with Bluetooth version 1.2). Bluetooth networks provide a way to connect and exchange information between devices such as mobile phones, telephones, laptops, personal computers, printers, GPS receivers, digital cameras, video game consoles, peripherals, etc.
Bluetooth and WiFi networks may both operate on the same frequency range (or overlapping frequency ranges), but they employ different modulation techniques. Bluetooth may be useful when transferring information between two or more devices that are near each other in low-bandwidth situations. For example, Bluetooth is commonly used to transfer sound data between a mobile phone and a Bluetooth-enabled wireless headset, or to transfer data between two proximately located hand-held devices (e.g., transferring files). On the other hand, WiFi provides capabilities similar to a traditional Ethernet network and provides much higher data rates as compared with Bluetooth. Also, because WiFi uses higher power than Bluetooth, WiFi communications can occur over greater distances than with Bluetooth.
Frequently, WLAN communication systems and Bluetooth communication systems coexist in sufficiently close proximity to one another that transmissions of one system may interrupt, degrade, or otherwise interfere with transmissions of the other system. For example, when a Bluetooth transmitter is located in close proximity to a WLAN receiver, transmit power emanating from the Bluetooth transmitter may desensitize and possibly saturate the WLAN receiver such that, during the Bluetooth transmission, a data packet being sent to the WLAN receiver by a WLAN access point, for example, either may not be received properly by the WLAN receiver or may even not be received at all. While this problem would not arise if WLAN data were transmitted only when the Bluetooth transmitter was off, in practice it is likely that WLAN and Bluetooth communication systems will overlap in time and interfere with one another to some degree.
For example, a Bluetooth/WLAN compatible communication device may be operating such that Bluetooth communications are in a Bluetooth Inquiry phase and WLAN communications are occurring with an Access Point (AP). The Bluetooth Inquiry phase can last as much as 10 seconds. During this period, if the AP does not receive a WLAN transmission from the computing device, the AP may either disassociate with the computing device or the transmission rate utilized by the AP for transmitting WLAN packets to the computing device may be dropped to a very low rate. This may result in the WLAN throughput going down to nearly zero.
In a Bluetooth network, a Bluetooth-enabled device may seek to discover what other Bluetooth-enabled devices are nearby. This may be accomplished by a Bluetooth inquiry procedure. In the inquiry procedure, the Bluetooth-enabled device broadcasts a series of inquiry messages. Each other Bluetooth-enabled device that receives one or more of the inquiry messages may respond by transmitting back to the Bluetooth-enabled device an inquiry reply message, which includes the address of the responding device. Based on the inquiry reply messages that it receives, the Bluetooth-enabled device can determine what other Bluetooth-enabled devices are nearby. Then, the Bluetooth-enabled device may seek to establish a connection with a selected one of the responding devices by transmitting a series of page messages to the selected responding device. In response, the selected device then transmits a page response message back to the Bluetooth-enabled device. Subsequently, additional information may be exchanged between the two devices to permit a Bluetooth connection to be established.